Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> wrote: > > nf_bridge is kmalloced blob with some extra information, including > > the bridge in and outports (mainly for iptables' physdev match). > > It also has various state bits so we know what manipulations > > have been performed by bridge netfilter on the skb (e.g. > > ppp header stripping). > > > > nf_bridge also provides scratch space where br_netfilter saves > > (and later restores) various things, e.g. ipv4 address for > > dnat detection, mac address to fix up ip fragmented skbs, etc. > > > > But in almost all cases we can avoid using ->data completely. > > I think one of the goals of this patchset is to prepare the removal of > that nf_bridge pointer from sk_buff which sounds as a good idea to me. > > Did you consider to implement this scratchpad area using a per-cpu > area? I mean, something similar to what we used to have in > ip_conntrack for events: I see that I misread part of what you wrote. We cannot use percpu data for nf_bridge_info; at least its not trivial to do (I tried). Main issues are: - nfqueue (we have to save/restore info) - local delivery (skb is enqueued in backlog) - skb is dropped (we need to reset scratch data) - DNAT mac hack (skb can be queued in qdisc). We _can_ use percpu data for passing the original mac header to the ip_fragment output function. But, as mentioned, there is a patch in netdev patchwork that adds extra output parameter for use with OVS so it seems cleaner to (re-) use common api in both OVS and br netfilter. > BTW, 6/8 I think needs some ifdef to make sure NF_CONNTRACK is in > placed. Right, thanks for catching this. > 7/8 needs NF_BRDIGE_MAX_MAC_HEADER_LENGTH which seems to have > a small typo in it, well these are dependent of 4/8 anyway. Sorry -- I'm dense -- what typo? :-) -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
